Eun Jin Chae MD, PhD, Presenter: Nothing to Disclose

Joon Beom Seo MD, PhD, Abstract Co-Author: Speaker, Siemens AG

Yeon-Mok Oh MD, PhD, Abstract Co-Author: Nothing to Disclose

Gladys G. Lo MD, Abstract Co-Author: Nothing to Disclose

Wing Hang Yeung MBCHB, FRCR, Abstract Co-Author: Nothing to Disclose

Seung Won Ra, Abstract Co-Author: Nothing to Disclose

Bing Lam, Abstract Co-Author: Nothing to Disclose

Sang Do Lee MD, PhD, Abstract Co-Author: Nothing to Disclose

To analyze ventilation abnormalities on xenon-enhanced CT in patients with obstructive lung diseases according to lung lesion patterns

Forty-seven subjects(M:F=35:12, mean age, 61.8 yrs) with obstructive PFT abnormality were enrolled from two centers. Patients’ diagnoses were COPD(32), asthma(4), bronchiolitis obliterans syndrome(3), diffuse panbronchiolitis(2), bronchitis(2), bronchiectasis(2), bronchopneumonia(1), and anthracofibrosis(1). All subjects underwent single phase, thoracic dual-energy CT using dual-source CT (Definition and FLASH, Siemens) when they inhaled 30% xenon for 90 seconds. Lung lesion pattern was evaluated on weighted average image and ventilation defect (VD) was evaluated on color-coded xenon map. In each lobe, lung lesion pattern in point of both airway and parenchyma, extent of ventilation defect per lesion(VD/lesion, %), and extent of ventilation defect per lobe(VD/lobe, %) were evaluated.

There was no noticeable change in monitored parameters in all subjects. Among 235 lobes of 47 patients, 231 lobes were evaluated and 4 lobes were excluded due to total collapse. Mean VD/lobe was 37.2%. In point of parenchyma, lesion patterns included centrilobular emphysema(CLE, n=82), panlobular emphysema(PLE, 8), hypoattenuation(78), bullous emphysema(1), ground glass opacity(1), and normal(61). In point of airway, lesion patterns included diffuse bronchial wall thickening(n=135), cellular bronchiolitis(56), large airway obstruction(6), bronchiectasis(4) and normal(30). The results of VD/lesion in point of parenchyma were: mild CLE, 34.6%; moderate CLE, 71.2%; severe CLE, 80.9%; moderate PLE, 90.0%; severe PLE, 100%; hypoattenuation, 96.4%. The results of VD/lesion in point of airway were: bronchial wall thickening, 35.3%; cellular bronchiolitis, 80.4%; large airway obstruction, lobar, 85%; segmental/subsegmental, 100%; bronchiectasis, 25.0%.

Areas of hypoattenuation, cellular bronchiolitis, segmental/subsegmental airway obstruction, and PLE showed relatively matched areas of ventilation defect, whereas areas of CLE, bronchial wall thickening, and bronchiectasis showed smaller extent of ventilation defect than anatomical extent.

Xenon ventilation CT may provide further insights into the pathophysiology of obstructive lung diseases.

Chae, E, Seo, J, Oh, Y, Lo, G, Yeung, W, Ra, S, Lam, B, Lee, S, Analysis of Ventilation Abnormalities in Patients with Obstructive Lung Diseases on Xenon-enhanced CT according to Lung Lesion Patterns: Multicenter Study.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9008371.html